The goal of this research is to isolate and characterize functionally distinct subpopulations of polymorphonuclear neutrophilic leukocytes (PMN) from normal and periodontally involved patients. The PMN has been shown to play a protective role against plaque organisms, contribute significantly to host defense of the gingival tissues and account for nearly all the host defense cells in the gingival crevice. Morphologically human peripheral blood PMNs (P-PMN) appear homogeneous and most research to date has considered them to also have functional homogeneity. Recently, the existence of functionally distinct subpopulations of PMNs has been demonstrated. It is virtually unknown what role PMN subpopulations play in the host's response during health, or during diseases, such as periodontal disease, in which decreased PMN activity is felt to be pathophysiologically important. The specific aims of this grant are: Aim 1) Develop affinity chromatographic techniques for whole cell PMN isolation based on cell surface characteristics utilizing the following ligands (lectins) bound to macrobeads of Sepharose 6MB: N-Formyl-Nle-Leu-Phe-Nle-Tyr-Lys-(NFTL), concanavalin A, casein, lotus tetragonolobus, gelatin and heparin. Aim 2) Isolate subpopulations of PMNs from: a) normal non-periodontally involved patients, b) localized juvenile periodontitis patients, and c) diabetic patients. Aim 3) Characterize the isolated PMN subpopulations' functional capacity to: a) be metabolically competent, b) respond chemotactically, c) migrate to the site of action, d) phagocytize, e) degranulate, f) show bactericidal competence. Whole cell affinity chromatography will be utilized to separate functionally unaltered PMN subpopulations based on the fact that differences in cell surface properties often parallel differences in functionally distinct cell populations. These isolated subpopulations will be subjected to a battery of function tests to assess their ability to mount an effective host response. In addition, the PMN subpopulation distribution of healthy versus periodontally diseased patients will be compared. Preliminary studies have successfully isolated PMN subpopulations based on differences in adherence to NFTL and ConA derivatized affinity columns. Furthermore the adherent PMN subpopulations demonstrate distinct differences in several functionality tests when compared to the non adherent subpopulation. This data strongly supports the feasibility of this proposal. The identification and characterization of PMN subpopulations may be of great value in understanding the PMN's role in maintaining active host defense or contributing to the pathology of patients with inflammatory diseases. This may be of considerable use in the detection and treatment of inflammatory diseases based on PMN dysfunction.